﻿<style type="text/css">
    #centerbox{
        position:relative;
        top:0px;
        left:0px;
        width:100%;
        height:100%;
        border:solid 1px black;
        background:white;
    }
    #centerbox > .container {
        position: absolute;
        top: 45%;
        left: 0px;
        text-align:center;
        border: solid 1px blue;
    }
</style>
<div id="centerbox">
    <div class="container">
        Loading...
    </div>
</div>